The polarizing light microscope (PLM) is one of the most versatile tools in the laboratory, permitting the analyst to characterize and identify a very large variety of different materials in addition to determining crystalline polymorphs. Most research-grade PLMs allow various adjustments to align the microscope for centration of components to the optical axis. The Olympus BHSP PLM allows three of the four objective mounts in the rotating objective nosepiece to be centered by using two custom centering wrenches that are supplied with the microscope when purchased new. The same wrenches are additionally used to adjust centering of the stage. Over time, the wrenches can become lost or misplaced, and the wrenches are rarely provided with the sale of a used BHSP microscope. Replacement centering wrenches are often needed. Appropriately sized jeweler's screwdrivers can be used, but these do not remain in place and attached to the nosepiece or stage centering screws while focusing or manipulating other parts of the microscope during the centration procedure. This article provides steps in making suitable replacement centering wrenches.